I think I may try either a) a tracing; or b) Photocopying onto card rather than paper......

Build Update:
Well, there's been a slight hiatus on the build this week due to being away sur le Continent for three days on business. Too much work, too much food, a little more beer than is usual on weekdays at Blink towers.... The diet starts here

Just before I left I did join the wing panels; which is when I discovered the limitations of the 'dihedral template to angle the wing rib' method of construction - or rather my abilities with the method!!. With hindsight, perhaps I should have built the outer panels with inboard rib vertical and the centre section without outboard wing ribs, then joined the panels at the correct dihedral using just the braces, then added the centre section ribs...but hindsight will always be 20/20 vision!

I did try adjusting the dihedral by careful sanding, but felt the ribs were getting structurally compromised (ie thin!). So I have joined at the correct angle using the braces, and where there are slight gaps where the ribs don't completely lay against each other, I will insert some carefully crafted slivers of balsa to ensure integrity. I have also noticed that I still need to add some gussets to the left outer panel (too keen to make the wing one piece!).

The structure as shown weighs (IIRC) about 6g... I have no idea whether that is good or bad; but the real worry is that the electric and radio componentry is currently standing at 77g without connectors...........

I think I may try either a) a tracing; or b) Photocopying onto card rather than paper......

Build Update:

The structure as shown weighs (IIRC) about 6g... I have no idea whether that is good or bad; but the real worry is that the electric and radio componentry is currently standing at 77g without connectors...........

Don't panic Colonel; the Sportster is a similar size (32" span) but has a lot less wing area than the Ajax (135 square inches) and is perfectly happy at 146 grams, I reckon it could easily be 20 - 40 grams more without impacting on the flying performance, so if you can keep it to 180 grams or less all up, which should be doable, it'll be fine. The Witch (36" and 170 square inches area) weighs just a touch more than the Sportster but is an absolute floater. For comparison the finished weight of the Sportster and Witch wings is 28 grams in both cases, so your wing should certainly be lighter than those.

I have just spent the best part of the last hour smiling while reading your thread Colonel. Apologies for the late arrival, been stretched at work for weeks. The build is coming along well and the banter and old photo's are very welcome. Thankfully I don't have any old snaps from the 70's here in AD....not sure if I have snaps anywhere, though my Dad might still have some in an old album somewhere.

I'm assuming Ilkley model shop is now long gone from the little hut aside the A65! Hence the longer trek to a model shop.

Don't panic Colonel.....if you can keep it to 180 grams or less all up, which should be doable, it'll be fine.

That's good news!! 150-180g is now the target - but it will be whatever it will be, and will be flung skywards however it turns out!

Quote:

Originally Posted by sparks59

I have just spent the best part of the last hour smiling while reading your thread Colonel. Apologies for the late arrival, been stretched at work for weeks. The build is coming along well and the banter and old photo's are very welcome. Thankfully I don't have any old snaps from the 70's here in AD....not sure if I have snaps anywhere, though my Dad might still have some in an old album somewhere. I'm assuming Ilkley model shop is now long gone from the little hut aside the A65! Hence the longer trek to a model shop.
Keep up the good work. sparks (also nothing to do with the band of the same name )

Hey, sparks! Glad to have you aboard, and glad you're enjoying the trip. I certainly am - I had forgotten just how totally relaxing furtling with balsa is! Mainly I work in half hour stints, though sometimes as little as 5 mins. In between times, I am thinking how best to do the next bit, be it sanding, cutting, designing or building. And there has been no model shop in Ilkley whilst I've been here - but that has only been 6 1/2 years - I'm still an offcummend!!!

Tailplane is now about 3/4 complete; I have adjusted the design a little as I wasn't too happy with the fin simply being stuck on top of the 1/16" sheeting on the centre bay of the tailplane. I have made mine so that the fin extends through the sheeting down to the t/p spar and is sandwiched between two more ribs spaced 3/32" apart similar to the Gipsy construction. Photos to follow soon.

After that, it looks like I will have to bite the bullet and start on the fuselage - which is the part I have been most looking forward to (as it is the most interesting) and the part I have been facing with most trepidation (as it is the part which has the most chance of being wrong with respect to rigging angles).....

Very true; and also Colonel, you will have two big "in flight trimming aids" which Jim doesn't have (and yes, I know, wouldn't want!) on his free-flight models - a proportional, trimmable, elevator and control of the amount of power. Providing the CG is in a reasonable place using these should ensure that the model gets down in one piece for any subsequent adjustment of the rigging angles.

... And there has been no model shop in Ilkley whilst I've been here - but that has only been 6 1/2 years - I'm still an offcummend!!!

looking at the google imagery, I reckonIlkley model shop was on the outer bend of Leeds road and Bath street, looks like a small building site now. It was a small shed, cant have been much more than 10' x 12'. Las time I can recall I think it had gone the way of many, becoming a knitting / handicraft store

Anyway, waiting with interest on the fuse, stick bodies are my favourite!
sparks.

Colonel, you will have two big "in flight trimming aids" which Jim doesn't have

I know - but I try not to think about them lest I get complacent to the extent of stupidity............. and when I said 'rigging angles' I was really euphemistically talking of my fear of ending up with a fuselage which Fyffes would be proud of....

The build - promised photos of the tailplane below. I had toyed with the idea of adding some lightening holes to the elevator. Attempted it with the first elevator using some Forstner bits in my hand drill - and totally wrecked the balsa! So unless I get bored with a scalpel in my hand, it is likely to stay solid. Checked the fin to tailplane fitment; it will be glued after covering.

My cork sheet arrived some time ago from my friends in the Spanish gasket factory; thereby proving that it ain't what you know (good!) but who you know.....it is actually nitrile bound cork granules - used for valve cover gaskets on older engines.. As such it is fairly heavy but pliable. The two great things about this are that
a) I can just lay it on my marble surface and it lays completely flat, and
b) pins go in easy, are held firmly, and come out without visible damage to the cork

Spent some time trying to find two lengths of 3/32" which were matched for stiffness. I did this by clipping pegs on the ends as a weight and picking two which bent by approximately the same amount. These are for the main lower longerons. The upper nose longerons were cut from one length to aid matching. Lower, upper fore and upper aft longerons were all soaked in water then pinned over the plan to the required curves and are currently drying.....

looking at the google imagery, I reckonIlkley model shop was on the outer bend of Leeds road and Bath street, looks like a small building site now. It was a small shed, cant have been much more than 10' x 12'. Las time I can recall I think it had gone the way of many, becoming a knitting / handicraft store

Definitely no moggle shop opposite Booth's supermarket nowadays - be blimmin' handy if there was! The reality is that most things are easily and quickly purchased online these days - but not for 'just another' strip of balsa!!

Having said that, I may end up having to order some balsa online for my next build...........

Really nice looking tail surfaces Colonel. Personally I wouldn't worry about lightening holes in the elevator on this one, although they are a good "posing aid"! If you need to do them in future, apart from spending large sums on "Softbore" (TM) tools, the best way is to forget any kind of drill bits and use a piece of 3/8" or 1/2" thin wall brass or dural tube, file the end into "teeth" and sharpen on the inside with a round back file. Drill the opposite end and insert a dowel "T" bar and use it in a twisting motion with the component held down firmly on, ideally, a self-healing cutting mat or other firm surface. A gentle clean up with a sandpaper wrapped dowel completes the job. Works a treat, it's all I ever use and I am addicted to posing - sorry - lightening holes! Mine is dural tube - see below which shows my "tool" with a Tom Tit X2 elevator.

Images

Really nice looking tail surfaces Colonel. Personally I wouldn't worry about lightening holes in the elevator on this one, although they are a good "posing aid"! If you need to do them in future, apart from spending large sums on "Softbore" (TM) tools, the best way is to forget any kind of drill bits and use a piece of 3/8" or 1/2" thin wall brass or dural tube, file the end into "teeth" and sharpen on the inside with a round back file. Drill the opposite end and insert a dowel "T" bar and use it in a twisting motion with the component held down firmly on, ideally, a self-healing cutting mat or other firm surface. A gentle clean up with a sandpaper wrapped dowel completes the job. Works a treat, it's all I ever use and I am addicted to posing - sorry - lightening holes! Mine is dural tube - see below which shows my "tool" with a Tom Tit X2 elevator.

You've gone to more trouble than I do - I just file the outside of the tube to an edge. This cuts holes nicely. The tubes are old arrows!

Well, you will have realised by now that I work in fits & starts - and the past week has been fairly light on opportunities to disappear loftwards. However this evening has been one of solitude, so after I'd been up the Moor to maiden a f*@my and then half an hour of repairing (don't ask), I set to with the Ajax fuz.....

The real bane has been 3/32" strips which vary in thickness...I know that is why all you Masters strip your own wood, but let me tell you - if I did it it would have been worse..!!!

Because the lower longeron has quite a severe curve in it, I am still concerned that there may be some stresses built in, and I am still worried that when I lift it from the board it may go 'Sproingggg!!!!' and one half will have the nose half an inch lower than the other. I have painted copious water onto the wood whilst pinned to the plan three times to try and combat this. It'll be fingers crossed during the Grand Unpinning Ceremony tomorrow night...